1. Field of the Invention
This invention relates to a novel organic compound and a liquid crystal composition containing the same. More particularly it relates to an organic compound having an optically active group and being useful as a component of ferroelectric liquid crystal compositions, and a ferroelectric liquid crystal composition containing the same.
2. Description of the Related Art
At present, TN (twisted nematic) display mode has been most broadly used as liquid crystal display elements and this TN liquid crystal display has a number of advantages such as low driving voltage, small power consumption, etc. However, it is inferior in the aspect of the response rate to emissive mode display elements such as cathode ray tube, electroluminescence, plasma display, etc. Further, a novel TN mode display element having its twist angle enlarged up to 180.degree.-270.degree. has also been developed, but it is still inferior in the aspect of the response rate As described above, efforts of various improvements have so far been made, but those having fully satisfactory performances have not yet been obtained. However, a novel display mode utilizing ferroelectric liquid crystals, the research of which has recently been extensively made, has a possibility of notably improving the response rate (Clark et al; Applied Phys. lett., 36, 899 (1980)). This mode utilizes chiral smectic phases such as chiral smectic C phase (hereinafter abbreviated to SC*). It is known that the phases exhibiting ferroelectric properties are not only limited to SC* phase, but phases of chiral smectic F, G, H, I, etc. also exhibit ferroelectric properties.
A number of specific features are required for ferroelectric liquid crystal materials to be practically used for ferroelectric liquid crystal display elements, but at present, there is no single compound which satisfies the requirements; hence it is necessary to use ferroelectric liquid crystal compositions obtained by mixing some liquid crystal compounds or non-liquid crystal compounds therewith.